Tank structure and method of erecting same

ABSTRACT

A concrete tank structure comprises a bottom slab, a plurality of inner and outer vertical columns arranged in circular arrays with each inner column spaced between and tied to a pair of outer columns, a plurality of wall panels each spanning one of the inner and one of the outer columns, and restraining means, preferably two or more cables, applied around all the outer columns for restraining their outward movement. According to a preferred method of erecting the tank and for introducing prestressing forces, a temporary structure is provided at the center and pulls inwardly on the inner columns before the restraining cables are applied to the outer columns.

United States Patent 1,247,958 11/1917 Holmes TANK STRUCTURE AND METHOD OF ERECTING SAME 10 Claims, 5 Qrawing Figs.

US. Cl 52/224, 52/248, 52/745 Int. Cl E04c 3/10, E04b l/ 14, E04g 11/04 Field of Search 52/ 192, 193; 52/224, 249, 245, 248, 745, 227-229 References Cited UNITED STATES PATENTS Primary Examiner-Henry C. Sutherland Assistant Examiner-James L. Ridgill, Jr. Attorney-Benjamin J. Barish ABSTRACT: A concrete tank structure comprises a bottom slab, a plurality of inner and outer vertical columns arranged in circular arrays with each inner column spaced between and tied to a pair of outer columns, a plurality of wall panels each spanning one of the inner and one of the outer columns, and restraining means, preferably two or more cables, applied around all the outer columns for restraining their outward movement. According to a preferred method of erecting the tank and for introducing prestressing forces, a temporary structure is provided at the center and pulls inwardly on the inner columns before the restraining cables are applied to the outer columns.

PATENTEUMAY 4mm 3577.692

I NVEN TOR ATTORNEY OSCAR SIRCOVICH TANK STRUCTURE AND METHOD OF ERECTING SAME BACKGROU ND OF THE INVENTION 1. Field of the Invention The present invention relates to a tank structure, particularly of concrete, and also to a method of erecting and prestressing the tank. The tank structure and method are particularly applicable with respect to the construction of large concrete tanks, e.g., water reservoirs.

2. Description of the Prior Art Large concrete tanks, particularly for use as water reservoirs, have been mainly made of concrete cast in situ. The tank so produced is thus permanent and cannot be dismantled and erected at another location. In addition, the time required for producing such a tank is long, and the cost high. Moreover, such a tank construction is very rigid and therefore may develop unforseen stresses producing cracks. Large concrete tanks have also been produced by using prefabricated elements, but as a rule they were secured together by permanent and rigid connections.

SUMMARY OF THE PRESENT INVENTION The present invention provides a tank structure which uses prefabricated concrete elements assembled together in a manner enabling the tank structure to be quickly erected and,

if need arises, dismantled as well, and which structure is nonrigid so that it can accommodate changes in stress minimizing the developing of cracks.

According to the present invention, there is provided a tank structure comprising a bottom slab, a group of outer and a group of inner vertical columns each arranged in a circular array with the inner columns staggered between the outer ones, and with each inner column tied between a pair of outer columns, a plurality of wall panels each spanning the distance between one of the inner and one of the outer vertical columns, tying means for tying each of the inner columns to the pair of outer columns disposed on its opposite sides, and restraining means applied around all the outer vertical column for restraining their outward movement.

The invention also provides a preferred method for erecting such a tank structure in which a temporary auxiliary structure is disposed in the center of the circular arrays of the columns. The inner (or outer) columns are connected to the auxiliary structure, and the latter is then caused to exert a pull on the connected columns, moving them, as well as the other group of columns and the panels between them, inwardly. The restraining elements are then applied around all the outer columns and the temporary auxiliary structure is removed.

Further features and advantages of the invention will be apparent from the description below.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention is herein described, somewhat diagrammatically and by way of example only, with reference to the accompanying drawings, wherein:

FIG. 1 is a top plan view of a tank structure constructed in accordance with the present invention;

FIG. 2 is a sectional view along lines II-II of FIG. 1;

FIG. 3 is a view similar to FIG. 2, but along lines IlIIII of FIG. 1 and also showing the temporary auxiliary structure used in erecting the tank; and

FIGS. 4 and 5 illustrate constructional details on an enlarged scale.

DESCRIPTION OF THE PREFERRED EMBODIMENT The tank structure illustrated in the drawings comprises a bottom slab 1 of concrete, which may be cast in situ or prefabricated, and which may have an upturned rim 2 at its periphery (FIG. 2). On this bottom slab are erected a plurality of upright or vertical concrete columns arranged in two circular arrays fonning concentric circles, namely an outer circular array of columns 3 and an inner circular array of columns 4.

panels contact the latter columns. Each of the inner columns 4 is tied, e.g. by a plurality of steel cables 7 fastened to elements 7 embedded in or secured to the columns, to the two neighboring outer columns 3 between which it is disposed.

In the preferred method of erecting the tanks, the foregoing elements are supported temporarily. A temporary auxiliary structure 6 (FIG. 3) is erected in the center of the circular arrays of the columns, and radial connecting elements 5 such as rigid rods or flexible steel cables, are connected between the temporary structure 6 and the inner columns 4. The radial connecting elements 5 are applied at different levels and at different angles between the temporary structure 6 and the inner columns 4 as shown in FIG. 3. The temporary structure 6 is then caused to exert an inward pull on all the inner columns 4, which displaces the latter columns inwardly, and since these columns are tied by elements 7 to the outer columns 3, the latter also move inwardly. This action also slightly displaces the panels 8 and presses them tightly against the edges of the spanned inner and outer columns. Restraining elements 9, preferably two or more vertically spaced steel cables, are then disposed around the outer columns 3, and the temporary structure 6 together with the radial connecting elements 5 are removed.

As shown in FIG. 3, the temporary structure 6 may merely be another vertical column supported on a member 10 which is actuated to cause the structure 6 to exert an inward pull on inner columns 4. A number of procedures may be used for causing structure 6 to exert this inward pull. For example, in one procedure member 10 may be a jack which is operated to cause the structure 6 to be raised, whereby inner columns 4 are pulled inwardly by means of the connecting elements 5. This is a preferable procedure since the lifting of the structure 6, which changes the angle of the connecting elements 5 causing the latter to exert the radial pull inwardly on the inner columns 4, also produces a vertical component of force acting I in an upward direction on columns 4, thereby reducing the friction with the bottom slab 1 so that the inward sliding of the columns occurs more smoothly. Another possible procedure is to use for supporting member 10 a member which is rotated or turned, e.g. l20200, winding part of the connecting elements 5 (e.g. wire cables) around the structure 6 and thereby pulling the inner columns 4 inwardly.

As shown in FIGS. 4 and 5 the contacting edges of columns 3 and 4 with panels 8 are preferably rounded so that the points of contact are linear, whereby the forces exerted by the water, when the tank is filled, or by the cables 9 in the opposite direction, will result in a very high local pressure along the contacting faces, providing a high degree of tightness. If necessary or desired, however, seals 12 (FIG. 4) may be applied at the juncture between the vertical columns 3 and 4, and the wall panels 8. In addition, seals 11 may also be placed on the bottom slab 1 at the junctures thereof with the vertical columns 3 and 4 and of the wall panels 8.

It will be appreciated that the foregoing tank structure may be produced at a relatively low cost, and may be quickly erected and dismantled as may be desired. It will also be seen that this structure is nonrigid and therefore can accommodate changes in stress minimizing the developing of cracks. For example, when the tank is filled with water, an outward pressure will be applied causing these elements to move slightly outwardly, and when the water is drained from the rank, these elements will move slightly inwardly under the urge of the cables 9.

In some cases, it may be desired to apply an outward force on the columns after the restraining cables are put into place. This can be done by using the temporary structure 6 and the connecting elements 5, but the latter would of course have to be rigid, e.g. rods or bars.

The columns 3 and 4, and the panels 8, may each consist of a plurality of prefabricated elements placed one on top of the other until the total height of the structure is achieved. A roof may also be applied. Also, the panels need not be flat, but may be shaped as desired. The tank may be used for granular material instead of liquids. Other changes, modifications and applications will be apparent.

I claim:

1. A tank structure, comprising a bottom slab, an outer group of vertical columns arranged in a circular array around said bottom slab, an inner group of vertical columns arranged in a circular array around said bottom slab with each disposed inwardly of said outer columns and between a pair of them, a plurality of wall panels each spanning the distance between and contacting the edges of one of said inner and one of said outer vertical columns, tying means tying each of said inner vertical columns to the pair of outer vertical columns disposed on opposite sides thereof, and restraining means applied around all said outer vertical columns restraining outward movement thereof.

2. A tank structure as defined in claim 1, wherein said tying means comprises a cable secured between each of said inner vertical columns and the pair of outer vertical columns disposed on opposite sides thereof.

3. A tank structure as defined in claim 1, wherein said restraining means comprises at least two vertically spaced cables disposed around said outer vertical columns.

4. A tank structure as defined in claim 1, further including seals at the junctures between said bottom slab and all said vertical columns and wall panels.

5. A tank structure as defined in claim 1, further including seals at the junctures between said vertical columns and said wall panels.

6. A tank structure as defined in claim 1, wherein all said vertical columns and wall panels are of concrete.

7. A method of erecting a tank structure comprising, disposing an outer group of vertical columns in a circular array and an inner group of vertical columns in a circular array with each of the inner columns located inwardly of the outer columns and between a pair of them, disposing a plurality of wall panels each spanning the distance between one of the inner and one of the outer vertical columns and each of the inner vertical columns tied to the pair of outer vertical columns disposed on opposite sides thereof; erecting a temporary auxiliary structure in the center of the circular arrays; connecting all the vertical columns of one of said groups to said temporary auxiliary structure by means of radial connecting elements; causing said temporary auxiliary structure to exert a pull on all said connected vertical columns, displacing them, as well as the other group of vertical columns and wall panels, radially inwardly; disposing restraining means around all the outer group of vertical columns and in contact therewith; and removing said temporary auxiliary structure.

8. The method as defined in claim 7, wherein said radial connecting elements are connected to the inner group of vertical columns.

9. The method according to claim 7, wherein said radial connecting elements are applied at different levels and at different angles between said temporary auxiliary structure and said connected vertical columns.

10. The method as defined in claim 7, wherein said pull is exerted by raising said temporary auxiliary structure. 

1. A tank structure, comprising a bottom slab, an outer group of vertical columns arranged in a circular array around said bottom slab, an inner group of vertical columns arranged in a circular array around said bottom slab with each disposed inwardly of said outer columns and between a pair of them, a plurality of wall panels each spanning the distance between and contacting the edges of one of said inner and one of said outer vertical columns, tying means tying each of said inner vertical columns to the pair of outer vertical columns disposed on opposite sides thereof, and restraining means applied around all said outer vertical columns restraining outward movement thereof.
 2. A tank structure as defined in claim 1, wherein said tying means comprises a cable secured between each of said inner vertical columns and the pair of outer vertical columns disposed on opposite sides thereof.
 3. A tank structure as defined in claim 1, wherein said restraining means comprises at least two vertically spaced cables disposed around said outer vertical columns.
 4. A tank structure as defined in claim 1, further including seals at the junctures between said bottom slab and all said vertical columns and wall panels.
 5. A tank structure as defined in claim 1, further including seals at the junctures between said vertical columns and said wall panels.
 6. A tank structure as defined in claim 1, wherein all said vertical columns and wall panels are of concrete.
 7. A method of erecting a tank structure comprising, disposing an outer group of vertical columns in a circular array and an inner group of vertical columns in a circular array with each of the inner columns located inwardly of the outer columns and between a pair of them, disposing a plurality of wall panels each spanning the distance between one of the inner and one of the outer vertical columns and each of the inner vertical columns tied to the pair of outer vertical columns disposed on opposite sides thereof; erecting a temporary auxiliary structure in the center of the circular arrays; connecting all the vertical columns of one of said groups to said temporary auxiliary structure by means of radial connecting elements; causing said temporary auxiliary structure to exert a pull on alL said connected vertical columns, displacing them, as well as the other group of vertical columns and wall panels, radially inwardly; disposing restraining means around all the outer group of vertical columns and in contact therewith; and removing said temporary auxiliary structure.
 8. The method as defined in claim 7, wherein said radial connecting elements are connected to the inner group of vertical columns.
 9. The method according to claim 7, wherein said radial connecting elements are applied at different levels and at different angles between said temporary auxiliary structure and said connected vertical columns.
 10. The method as defined in claim 7, wherein said pull is exerted by raising said temporary auxiliary structure. 